Improve alternatives search

app/src/main/kotlin/org/koitharu/kotatsu/alternatives/domain/AlternativesUseCase.kt

@@ -12,6 +12,7 @@ import org.koitharu.kotatsu.core.util.ext.almostEquals
 import org.koitharu.kotatsu.explore.data.MangaSourcesRepository
 import org.koitharu.kotatsu.parsers.model.Manga
 import org.koitharu.kotatsu.parsers.model.MangaListFilter
+import org.koitharu.kotatsu.parsers.model.MangaSource
 import org.koitharu.kotatsu.parsers.util.runCatchingCancellable
 import javax.inject.Inject
 
@@ -24,7 +25,7 @@ class AlternativesUseCase @Inject constructor(
 ) {
 
 	suspend operator fun invoke(manga: Manga): Flow<Manga> {
-		val sources = sourcesRepository.getEnabledSources()
+		val sources = getSources(manga.source)
 		if (sources.isEmpty()) {
 			return emptyFlow()
 		}
@@ -55,6 +56,14 @@ class AlternativesUseCase @Inject constructor(
 		}
 	}
 
+	private suspend fun getSources(ref: MangaSource): List<MangaSource> {
+		val result = ArrayList<MangaSource>(MangaSource.entries.size - 2)
+		result.addAll(sourcesRepository.getEnabledSources())
+		result.sortByDescending { it.priority(ref) }
+		result.addAll(sourcesRepository.getDisabledSources().sortedByDescending { it.priority(ref) })
+		return result
+	}
+
 	private fun Manga.matches(ref: Manga): Boolean {
 		return matchesTitles(title, ref.title) ||
 			matchesTitles(title, ref.altTitle) ||
@@ -66,4 +75,11 @@ class AlternativesUseCase @Inject constructor(
 	private fun matchesTitles(a: String?, b: String?): Boolean {
 		return !a.isNullOrEmpty() && !b.isNullOrEmpty() && a.almostEquals(b, MATCH_THRESHOLD)
 	}
+
+	private fun MangaSource.priority(ref: MangaSource): Int {
+		var res = 0
+		if (locale == ref.locale) res += 2
+		if (contentType == ref.contentType) res++
+		return res
+	}
 }

app/src/main/kotlin/org/koitharu/kotatsu/alternatives/ui/AlternativeAD.kt

@@ -43,7 +43,11 @@ fun alternativeAD(
 	bind { payloads ->
 		binding.textViewTitle.text = item.manga.title
 		binding.textViewSubtitle.text = buildSpannedString {
-			append(context.resources.getQuantityString(R.plurals.chapters, item.chaptersCount, item.chaptersCount))
+			if (item.chaptersCount > 0) {
+				append(context.resources.getQuantityString(R.plurals.chapters, item.chaptersCount, item.chaptersCount))
+			} else {
+				append(context.getString(R.string.no_chapters))
+			}
 			when (item.chaptersDiff.sign) {
 				-1 -> inSpans(ForegroundColorSpan(colorRed)) {
 					append("  ▼ ")

app/src/main/kotlin/org/koitharu/kotatsu/alternatives/ui/AlternativesViewModel.kt

@@ -25,6 +25,7 @@ import org.koitharu.kotatsu.list.ui.model.ListModel
 import org.koitharu.kotatsu.list.ui.model.LoadingFooter
 import org.koitharu.kotatsu.list.ui.model.LoadingState
 import org.koitharu.kotatsu.parsers.model.Manga
+import org.koitharu.kotatsu.parsers.util.runCatchingCancellable
 import javax.inject.Inject
 
 @HiltViewModel
@@ -44,9 +45,11 @@ class AlternativesViewModel @Inject constructor(
 
 	init {
 		launchJob(Dispatchers.Default) {
-			val ref = mangaRepositoryFactory.create(manga.source).getDetails(manga)
+			val ref = runCatchingCancellable {
+				mangaRepositoryFactory.create(manga.source).getDetails(manga)
+			}.getOrDefault(manga)
 			val refCount = ref.chaptersCount()
-			alternativesUseCase(manga)
+			alternativesUseCase(ref)
 				.map {
 					MangaAlternativeModel(
 						manga = it,
@@ -69,6 +72,7 @@ class AlternativesViewModel @Inject constructor(
 				}.collect {
 					content.value = it
 				}
+			content.value = content.value.filterNot { it is LoadingFooter }
 		}
 	}
 

app/src/main/kotlin/org/koitharu/kotatsu/core/exceptions/UnsupportedSourceException.kt

@@ -0,0 +1,8 @@
+package org.koitharu.kotatsu.core.exceptions
+
+import org.koitharu.kotatsu.parsers.model.Manga
+
+class UnsupportedSourceException(
+	message: String?,
+	val manga: Manga?,
+) : IllegalArgumentException(message)

app/src/main/kotlin/org/koitharu/kotatsu/core/exceptions/resolve/ErrorObserver.kt

@@ -21,7 +21,7 @@ abstract class ErrorObserver(
 	private val onResolved: Consumer<Boolean>?,
 ) : FlowCollector<Throwable> {
 
-	protected val activity = host.context.findActivity()
+	protected open val activity = host.context.findActivity()
 
 	private val lifecycleScope: LifecycleCoroutineScope
 		get() = checkNotNull(fragment?.viewLifecycleScope ?: (activity as? LifecycleOwner)?.lifecycle?.coroutineScope)
@@ -36,7 +36,7 @@ abstract class ErrorObserver(
 	private fun isAlive(): Boolean {
 		return when {
 			fragment != null -> fragment.view != null
-			activity != null -> !activity.isDestroyed
+			activity != null -> activity?.isDestroyed == false
 			else -> true
 		}
 	}

app/src/main/kotlin/org/koitharu/kotatsu/core/exceptions/resolve/ExceptionResolver.kt

@@ -8,13 +8,16 @@ import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentActivity
 import okhttp3.Headers
 import org.koitharu.kotatsu.R
+import org.koitharu.kotatsu.alternatives.ui.AlternativesActivity
 import org.koitharu.kotatsu.browser.BrowserActivity
 import org.koitharu.kotatsu.browser.cloudflare.CloudFlareActivity
 import org.koitharu.kotatsu.core.exceptions.CloudFlareProtectedException
+import org.koitharu.kotatsu.core.exceptions.UnsupportedSourceException
 import org.koitharu.kotatsu.core.ui.dialog.ErrorDetailsDialog
 import org.koitharu.kotatsu.core.util.TaggedActivityResult
 import org.koitharu.kotatsu.parsers.exception.AuthRequiredException
 import org.koitharu.kotatsu.parsers.exception.NotFoundException
+import org.koitharu.kotatsu.parsers.model.Manga
 import org.koitharu.kotatsu.parsers.model.MangaSource
 import org.koitharu.kotatsu.settings.sources.auth.SourceAuthActivity
 import kotlin.coroutines.Continuation
@@ -59,6 +62,11 @@ class ExceptionResolver : ActivityResultCallback<TaggedActivityResult> {
 			false
 		}
 
+		is UnsupportedSourceException -> {
+			e.manga?.let { openAlternatives(it) }
+			false
+		}
+
 		else -> false
 	}
 
@@ -77,6 +85,11 @@ class ExceptionResolver : ActivityResultCallback<TaggedActivityResult> {
 		context.startActivity(BrowserActivity.newIntent(context, url, null))
 	}
 
+	private fun openAlternatives(manga: Manga) {
+		val context = activity ?: fragment?.activity ?: return
+		context.startActivity(AlternativesActivity.newIntent(context, manga))
+	}
+
 	private fun getFragmentManager() = checkNotNull(fragment?.childFragmentManager ?: activity?.supportFragmentManager)
 
 	companion object {
@@ -86,6 +99,7 @@ class ExceptionResolver : ActivityResultCallback<TaggedActivityResult> {
 			is CloudFlareProtectedException -> R.string.captcha_solve
 			is AuthRequiredException -> R.string.sign_in
 			is NotFoundException -> if (e.url.isNotEmpty()) R.string.open_in_browser else 0
+			is UnsupportedSourceException -> if (e.manga != null) R.string.alternatives else 0
 			else -> 0
 		}
 

app/src/main/kotlin/org/koitharu/kotatsu/core/parser/DummyParser.kt

@@ -0,0 +1,38 @@
+package org.koitharu.kotatsu.core.parser
+
+import org.koitharu.kotatsu.core.exceptions.UnsupportedSourceException
+import org.koitharu.kotatsu.parsers.MangaLoaderContext
+import org.koitharu.kotatsu.parsers.MangaParser
+import org.koitharu.kotatsu.parsers.config.ConfigKey
+import org.koitharu.kotatsu.parsers.model.Manga
+import org.koitharu.kotatsu.parsers.model.MangaChapter
+import org.koitharu.kotatsu.parsers.model.MangaListFilter
+import org.koitharu.kotatsu.parsers.model.MangaPage
+import org.koitharu.kotatsu.parsers.model.MangaSource
+import org.koitharu.kotatsu.parsers.model.MangaTag
+import org.koitharu.kotatsu.parsers.model.SortOrder
+import java.util.EnumSet
+
+/**
+ * This parser is just for parser development, it should not be used in releases
+ */
+class DummyParser(context: MangaLoaderContext) : MangaParser(context, MangaSource.DUMMY) {
+
+	override val configKeyDomain: ConfigKey.Domain
+		get() = ConfigKey.Domain("localhost")
+
+	override val availableSortOrders: Set<SortOrder>
+		get() = EnumSet.allOf(SortOrder::class.java)
+
+	override suspend fun getDetails(manga: Manga): Manga = stub(manga)
+
+	override suspend fun getList(offset: Int, filter: MangaListFilter?): List<Manga> = stub(null)
+
+	override suspend fun getPages(chapter: MangaChapter): List<MangaPage> = stub(null)
+
+	override suspend fun getAvailableTags(): Set<MangaTag> = stub(null)
+
+	private fun stub(manga: Manga?): Nothing {
+		throw UnsupportedSourceException("Usage of Dummy parser", manga)
+	}
+}

app/src/main/kotlin/org/koitharu/kotatsu/core/util/ext/Throwable.kt

@@ -17,6 +17,7 @@ import org.koitharu.kotatsu.core.exceptions.EmptyHistoryException
 import org.koitharu.kotatsu.core.exceptions.SyncApiException
 import org.koitharu.kotatsu.core.exceptions.TooManyRequestExceptions
 import org.koitharu.kotatsu.core.exceptions.UnsupportedFileException
+import org.koitharu.kotatsu.core.exceptions.UnsupportedSourceException
 import org.koitharu.kotatsu.core.exceptions.WrongPasswordException
 import org.koitharu.kotatsu.parsers.ErrorMessages.FILTER_BOTH_LOCALE_GENRES_NOT_SUPPORTED
 import org.koitharu.kotatsu.parsers.ErrorMessages.FILTER_BOTH_STATES_GENRES_NOT_SUPPORTED
@@ -56,6 +57,7 @@ fun Throwable.getDisplayMessage(resources: Resources): String = when (this) {
 
 	is WrongPasswordException -> resources.getString(R.string.wrong_password)
 	is NotFoundException -> resources.getString(R.string.not_found_404)
+	is UnsupportedSourceException -> resources.getString(R.string.unsupported_source)
 
 	is HttpException -> getHttpDisplayMessage(response.code, resources)
 	is HttpStatusException -> getHttpDisplayMessage(statusCode, resources)
@@ -98,6 +100,10 @@ fun Throwable.isReportable(): Boolean {
 	return this is Error || this.javaClass in reportableExceptions
 }
 
+fun Throwable.isNetworkError(): Boolean {
+	return this is UnknownHostException || this is SocketTimeoutException
+}
+
 fun Throwable.report() {
 	val exception = CaughtException(this, "${javaClass.simpleName}($message)")
 	exception.sendWithAcra()

app/src/main/kotlin/org/koitharu/kotatsu/details/ui/DetailsActivity.kt

@@ -36,7 +36,6 @@ import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.flow.FlowCollector
 import kotlinx.coroutines.flow.filterNotNull
 import org.koitharu.kotatsu.R
-import org.koitharu.kotatsu.core.exceptions.resolve.SnackbarErrorObserver
 import org.koitharu.kotatsu.core.model.parcelable.ParcelableManga
 import org.koitharu.kotatsu.core.os.AppShortcutManager
 import org.koitharu.kotatsu.core.parser.MangaIntent
@@ -125,19 +124,7 @@ class DetailsActivity :
 		viewModel.manga.filterNotNull().observe(this, ::onMangaUpdated)
 		viewModel.onMangaRemoved.observeEvent(this, ::onMangaRemoved)
 		viewModel.newChaptersCount.observe(this, ::onNewChaptersChanged)
-		viewModel.onError.observeEvent(
-			this,
-			SnackbarErrorObserver(
-				host = viewBinding.containerDetails,
-				fragment = null,
-				resolver = exceptionResolver,
-				onResolved = { isResolved ->
-					if (isResolved) {
-						viewModel.reload()
-					}
-				},
-			),
-		)
+		viewModel.onError.observeEvent(this, DetailsErrorObserver(this, viewModel, exceptionResolver))
 		viewModel.onActionDone.observeEvent(
 			this,
 			ReversibleActionObserver(viewBinding.containerDetails, viewBinding.layoutBottom),

app/src/main/kotlin/org/koitharu/kotatsu/details/ui/DetailsErrorObserver.kt

@@ -0,0 +1,56 @@
+package org.koitharu.kotatsu.details.ui
+
+import com.google.android.material.snackbar.Snackbar
+import org.koitharu.kotatsu.R
+import org.koitharu.kotatsu.core.exceptions.UnsupportedSourceException
+import org.koitharu.kotatsu.core.exceptions.resolve.ErrorObserver
+import org.koitharu.kotatsu.core.exceptions.resolve.ExceptionResolver
+import org.koitharu.kotatsu.core.ui.dialog.ErrorDetailsDialog
+import org.koitharu.kotatsu.core.util.ext.getDisplayMessage
+import org.koitharu.kotatsu.core.util.ext.isNetworkError
+import org.koitharu.kotatsu.parsers.exception.NotFoundException
+import org.koitharu.kotatsu.parsers.exception.ParseException
+
+class DetailsErrorObserver(
+	override val activity: DetailsActivity,
+	private val viewModel: DetailsViewModel,
+	resolver: ExceptionResolver?,
+) : ErrorObserver(
+	activity.viewBinding.containerDetails, null, resolver,
+	{ isResolved ->
+		if (isResolved) {
+			viewModel.reload()
+		}
+	},
+) {
+
+	override suspend fun emit(value: Throwable) {
+		val snackbar = Snackbar.make(host, value.getDisplayMessage(host.context.resources), Snackbar.LENGTH_SHORT)
+		if (value is NotFoundException || value is UnsupportedSourceException) {
+			snackbar.duration = Snackbar.LENGTH_INDEFINITE
+		}
+		when {
+			canResolve(value) -> {
+				snackbar.setAction(ExceptionResolver.getResolveStringId(value)) {
+					resolve(value)
+				}
+			}
+
+			value is ParseException -> {
+				val fm = fragmentManager
+				if (fm != null) {
+					snackbar.setAction(R.string.details) {
+						ErrorDetailsDialog.show(fm, value, value.url)
+					}
+				}
+			}
+
+			value.isNetworkError() -> {
+				snackbar.setAction(R.string.try_again) {
+					viewModel.reload()
+				}
+			}
+		}
+		snackbar.show()
+	}
+}

app/src/main/res/values/strings.xml

@@ -637,4 +637,5 @@
 	<string name="long_ago_read">Long time ago read</string>
 	<string name="unread">Unread</string>
 	<string name="enable_source">Enable source</string>
+	<string name="unsupported_source">This manga source is not supported</string>
 </resources>